Feed water regulator



July W, 1934 H. J. MAsTENBRooK 1,966,898

FEED WATER REGULATOR FildApril 9. 1930 3 Sheets-Shea?l l 790 g 32 l 2202 /a /7 /9 2 /3 July 17, 1934. HJ. MASTENBROOK FEED WATER REGULATOR Filed April 9. 1930 3 Sl'xeecs-Sheei'l 2 HFA/FV l' NAT/ENBPOOK mais MY 17 1934. H. J. MAsTENBRooK FEED WATER REGULATOR Filed April 9, 1930 3 Sheets-Sheet 3 www w mw M ww QW bw wm, f( hh, PQR@ Wh, w www N grt/venten l l l HENRI J' M145 TE/VB/POOK Patented July 17, 1934 UNlTED STATES hiTNT GFFCE FEED WATER REGULATOR Henry J. Mastenbroek, Cleveland, Chio, assigner This invention relates to now, particularly the steam boiler.

to The Swartwout Company,

ka corporation of Ohio Cleveland, Ohio,

Application April 9, 1930, Serial No. 442,787

16 Claims.

a control of iiuid iiow of feed water to a In order to obtain accurate automatic control of boiler feed water it has been proposed in United States Letters Patent No. 1,396,239, is-

sued November 8, 1921 to R. W, Andrews, to provide a feed water valve movable in response to changes in boiler water level and a dierential pressure valve 'for maintaining a constant drop across the feed water valve. ment over this arrangement is co-pending applicatio Serial No. 27,735,

An improvedisclosed in the n of Joseph M. Barrett,

filed May 4, 1925, wherein manually operated needle valves are employed to control different connections to one of the luid pressure chambers of valve.

A departure from the diierential the disclosure of the Andrews patent involving a distinctly new mode of operation is illustrated in the application of Joseph M, Barrett, Qctober 22, 1926, in across the feed water teren-tial valve in response An improvement over this construcconditions.

Serial No. 143,326, led which the pressure drop valve is varied by the difto changes in boiler tion is shown in my co-pending application Serial No. 324,187, led December 6, 1928, in which a pilot valve is employed to amplify the presfrom the pressure drop across generator and thereby Vary the the feed water valve.

The principal object of this invention is to obtain an accurate and sensitive control of feed water new in accordance with the requirements or a boiler by moving the feed water valve in response to changes in boiler conditions, and

further altering the position of the feed water valve to compensate for variations in pressure in the .system which might otherwise affect the flow through the valve.

More speciiically, this invention contemplates the control of feed water flow by a single diiierential pressure valve.

Other objects are to impress changes in boiler conditions upon the the medium oi feed water valve through a pilot valve in order to obtain a more sensitive control; to utilize a diierential valve of the diaphragm or piston actuated type trol installations.

In the accompanyin g drawings, which in conjunction with the following description disclose .specic applications of the invention:

Fig. 1 is a vertical medial section through a feed water valve and pilot valve constructed in accordance with this invention. 50

Fig. 2 is a diagrammatic layout illustrating the improved feed water control apparatus associated with a boiler.

Fig, 3 is a diagrammatic sectional modified form of valve.

Fig. 4 is a diagrammatic sectional View of a third form of Valve.

Referring to Figs. l and 2 of the drawings, the boiler is connected by means of a conduit 6 to the outlet .side of a balanced valve casing 7, the inlet side of which is connected to a feed water pipe 8. An extension casing 9 is bolted to an open side of the casing 7 and houses a valve stem 10 which carries a closure member 11, the latter being movable to control the ow through the valve 7. The free end of the valve .stem l0 is connected to a diaphragm 12 enclosed within a chamber formed by the upper end of the easing 9 and a cap 13. A spring 14 is also housed within the casing 9 and has one 80 end bearing against the diaphragm 12 to urge the valve closure member to closed position. The opposite end of the spring 14 bears against an arm 15 which is mounted on a shank 16 journalled in the casing 9, and which may be moved vertically by rotation of the shank 16 to adjust the tension of the spring.

The casing 9 is open throughout its length to establish on the under side of the diaphragm 12 the pressure existing on the outlet side of the Valve 7. Fluid pressures are established on the upper side oi the diaphragm 12 through a conduit 17 which opens into the interior of the cap 13 and which if desired, may be provided with a needle valve 18. The opposite end oi the conduit 17 opens into a three way pilot valve 19 which includes a closure member 20 movable in the chamber 21 to control communication between the same and the chambers 22 and 23. The closure member 2O is carried by a valve stem 24 normally urged by the spring 25 to a position sealing the passage way between the chambers 21 and 23. The end oi the valve stem 24 carries a diaphragm enclosed within the diaphragm chamber 26 and arranged to be subjected to iiuid pressure opposing the force of the spring 25. The fluid pressure is conducted to the diaphragm chamber 26 by a conduit 27 leading from a generator 28 mounted on a tube 29 spanning the Water level in the boiler. This installation may be view of a .14 and open the feed water valve 7.

similar to that disclosed in Patent Number 1,193,125, issued August l, 1916 to N. G. Copley, and may be arranged to create a fluid pressure varying in accordance with changes in water level, or changes in load, or both, in accordance with the, requirements of a particular system.

The chamber 21 of the pilot valve 19 is connected by a conduit to the conduit 6, and the chamber 23 is connected by a conduit 31 to the inlet side of the feed water valve 7. Needle valves 32 and 33 are preferably disposed in the conduits 30 and 31 respectively. It is to be noted that the seats of the pilot valve are readily adjustable toward or away from each other. This construction is described and claimed in detail in my copending application Serial No. 451,560, led May 12, 1930.

Sufficient resistance to flow is preferably established between the valve 7 and the boiler 5 to cause an appreciable pressure drop between these points. This resistance may consist merely of the line friction of the conduit 6,or may be artificially increased by means of a hand valve or a restriction of any suitable type. In Figs. 1 and 2 an annular erice plate 34 having an internal bore smaller in diameter than the internal diameters of the pipes 6 and 8 is illustrated as secured between the pipe 6 and the casing of the valve 7. In the embodiment shown the pipe 6 is counterbored to provide a recess 36 of sufficient depth to seat the plate 34 flush with the end of the pipe 6.

In operation the spring 14 normaly holds the valve closure 11 in closed position in the absence l of fluid pressure acting upon the diaphragm l2.

The conditions existincr in the boiler 5 are reected by the generator 23 to the diaphragm chamber 26 of the pilot valve 19; a lowered water level or increased load on the boiler causing a greater pressure in the diaphragm chamber 26, and a higher water level or decreased load causing a decrease in the pressure in the diahragm chamber. When the pressure in the diaphragm chamber 26 overcomes the force of the spring 25 the closure member 20 of the pilot valve moves upwardly to establish communication between the chambers 2l and 23 and reduce the area of the opening between the chambers 21 and 22. Fluid at pump pressure from the pipe 8 is admitted through the conduit 31 to the cham- 'oer 21 and flows through the conduit 30 to the pipe 6. The pressure drop from the chamber 21 to the pipe 6 is reflected through the conduit 17 to the upper side of the diaphragm 12, causing the same to move against the force of the spring Feed water then flows from the pipe 8 through the valve 7 to the boiler, the tensions of the springs 14 and 25 and the line frictions in the various conduits being adjusted so that quantity of water entering the boiler accords with the requirements of the boiler conditions producing the pressure in the diaphragm chamber 26. The line friction in the conduits 17, 3G and 31 is adjusted by properly positioning the needle valves 18, 32 and 33, respectively.

By reason of the restricted orifice 35 the fluid pressure existing at the outlet side of the valve 7, which equal to the fluid pressure exerted against the under side of the diaphragm 12, is greater than the pressure in the boiler 5. This pressure drop across the orifice 35 or other resistance between the valve 7 and the boiler 5 is so preferably proportioned with respect to the line frictions in the conduits 30 and 31 that an increase in pressure in the feed water pipe 8 causes a greater increase on the under side of the diaphragm l2 than on the upper side thereof, causing the closure member 1l to move slightly toward closed position and maintain the quantity of iluid flowing therethrough substantially constant. Changes in boiler conditions which necessitate changes in the quantity of feed water entering the boiler in order to maintain the proper water level cause changes of pressure in the diaphragm chamber 26 of the pilot valve, thereby moving the closure member 20 and varying the restriction between the chamber 21 and the chambers 22 and 23. Such changes vary the pressure on the upper side of the diaphragm 12 and move the closure 11 of the feed water valve 7 to increase or decrease the flow. It will therefore be seen that -in normal operation the closure member 20 iioats between its opposed seats allowing a continuous flow through the conduits 30 and 3l with more or less of the pressure of the fluid being transmitted through the conduit 17 to the upper side of the diaphragm 12. The closure member 1l similarly remains partially open allowing a continuous flow of feed water to the boiler. Variations in pressure in the feed water line 8 move the closure member 11 to compensate therefor and maintain the quantity of water entering the boiler constant for any given pressure existing in the diaphragm chamber 26.

In the modication shown in Fig. 3, the feed water valve 37 is provided with a closure 38 arranged to seat and close the valve when the valve stem 39 is moved downwardly. A casing 43 ses cured to the open side of the valve 37 allows the pressure fluid of the outlet side of the valve to act against the under side of the piston 40. A conduit 44 communicates with the chamber 22 of the pilot valve 19 and with the feed water pipe 8. A conduit 45 opens into the chamber 23 of the pilot valve 19 and into the casing 43 of the feed water valve. The chamber 21 of the pilot valve is connected to the piston chamber 41 by a conduit 46. Needle valves 47 are preferably disposed in each of the conduits 44, 45, and 46. A

hand valve 48 is placed in the pipe 6 between the feed water valve 37 and the boiler 5 as an alternative means for providing the desired pressure drop between the feed water valve and the boiler, although in this modification the pressure drop is not essential to the operation.

In the operation of the valve shown in Figure 3 the outlet pressure of the valve and the force of the spring tend to move the valve closure 38 to open position. The pressure of the feed water in the pipe 3 acts through the conduit 44 against 'the upper side of the piston 40 to hold the valve in closed position. Pressure from the generator 28 is conducted to the diaphragm chamber 26 of the pilot valve and moves the same to restrict communication between the chambers 21 and 22 and open communication from the chamber 21 to the chamber 23. The consequent decrease in pressure against the upper side of the piston 40 allows'the feed water valve closure 38 to move to open position. The springs of the valves and the line friction in the various conduits are adjusted so that the proper quantity of water enters the boiler at all times in accordance with the boiler conditions reflected through the generator 23, When the pressure in the feed line 8 is constant. Surges of pressure in the feed water line 8 increase the pressure existing in the conduit 44. The consequent increase of pressure drop across the pilot .valve 19 increases the .pressure acting on the upper side of the piston 40 and moves the valve 38 towards closed position. The lconduit 44 is preferably relatively large, so that surges will be readily reiiected to the piston 40. Increases of pressure against the upper side of the piston 40 tend to be balanced by the increased pressure of the spring 42 after the piston has moved a short distance. A needle valve 47 in -the conduit 46 is normally maintained sufliciently restricted to prevent hammering of the valve closure 3S against the seat under sudden vsurges of pressure in the feed line 8. 1f desired the hand valve 48 may be slightly restricted in order to provide an increase in fluid pressure against the under side of the piston 49 when the valve closure 3S is operating in a widely opened position and the spring 42 is consequently extended.

In the modifications shown in Fig'. 4 the feed water valve 49 is similar in construction to the valve 7 illustrated in Fig. 1 except that the spring 5() is arranged to exert a pressure on the valve stem 51 normallyl urging the valve toward open position. The pipe 6 is provided with a restriction of any suitable type, a hand valve 48 being illustrated. A three-way pilot valve 19 associated with the generator 28 in the manner described in connection with' Figs. 1 to 3 is arranged to control the fluid pressure on the upper side of the diaphragm 52, the lower side of the diaphragm being subjected to the pressure of the outlet side of the valve 49. A conduit 53 leads from the chamber 23 of the pilot valve 19 to the pipe 6, opening into the latter at a point between the hand valve 48 and the boiler. The chamber 22 of the pilot valve 19 is open to atmosphere through a conduit 54, and the chamber 21 is connected to the diaphragm chamber 55 of the valve 49 by a conduit 56. Needle valves 57 are provided in the conduits 53. 54, and 56 to adjust the line friction.

1n the absence of pressure in the diaphragm chamber 26 the spring 25 ofthe pilot valve 19 holds the valve closure in position to establish communication between the chambers 21 and 22 and seal the chamber 23 from the chamber 21. The upper side of the diaphragm 52 is accordingly subjected to atmospheric pressure and the lower side is subjected to boiler pressure through the pipe 6, which is sufficient to hold the valve 49 in closed position. When a flow of feed water is required by the boiler the generator 28 creates sufficient pressure in the diaphragm chamber 26 of the pilot valve to establish communication between the chambers 23 and 21, thereby placing a fluid pressure on the upper side of the diaphragm 52. The various parts are adjusted in such a manner that this fluid pressure opens 'the valve 49 sufficiently to permit the desired quantity of feed water to flow into the boiler. An increase in pressure in the feed line 8 acts to increase the back pressure between the outlet side of the valve 49 and the hand valve 48, which in turn acts against the under side of the diaphragm 52 to move the valve slightly toward closed position and maintain the flow constant. It will accordingly be seen that a constant flow is maintained for any given pressure in thel diaphragm chamber 26, irrespective of pressure changes in the feed line 8.

1n each of the various forms of valves which I have described means are preferably provided to create a resistance to iiow between the feed water valve and the boier.v 1t is to be understood that this resistance may be obtained, in anyform of the valve, by the apertured plate 34 illustrated in Fig. 1, the hand valve 48 shown in Figs. 3

and 4, or any other type of flow resistance such as the line friction in the boiler feed pipe 6. The resistance which may be found desirable in a particular installation is determined when the valve is installed and needA not be further changed. This resistance is therefore relatively fixed, and the expression fixed resistance will be used hereinafter to designate a resistance which may be varied as desired when the valve-is installed but which need not thereafter be changed. It is also to be understood that the needle valves shown in the various conduits which conduct pressure fluid to and from the diaphragm chambers of the feed water valves are merely illustrative of means to provide any desired restriction in these conduits. 1n practice, it might be found desirable to make these conduits of the proper internal diameter and length to provide the necessary line friction for given pressure conditions without utilizing the needle valves. It is also to be understood that the three way pilot valve illustrated in each of the various figures might be repiaced by a master control consisting of two separate diaphragm actuated valves, such as illustrated in the copending application of Howard S. Fraser, Serial No. 320,836, led November 21, 1928. The diaphragm illustrated in Figs. 1, 2, and 4 in the feed water valve, and the piston illustrated in Fig. 3 are considered to be substantial equivalents, and it is to be understood that either one of these members, for any other type of movable part, might be used with any form of the valve.

While the foregoing description is necessarily of a detailed character in order that the invention may be fully set forth it is to be understood that the specific terminology employed is not to be construed as restrictive or limiting, and it is to be further understood that various modifications and rearrangements of parts may be resorted to without departing from the scope of the invention as claimed herein.

I claim:

1. The method of feeding a boilei which consists of varying the opening of a feed water regulating valve in response to changes in boiler conditions, and in addition varying the opening of said valve in response to changes in pressure conditions in the feed water line ahead of said valve to maintain the flow through said valve constant for given boiler conditions.

2. The combination of a boiler, a feed Water pipe, a feed water valve for controlling the flow of feed water to said boiler, variable means for controlling the movement of said feed water valve in accordance with changes in boiler conditions including means controlled by said variable means for controlling the movement of said feed water valve to maintain the iiow therethrough a constant predetermined function of the flow permitted by said variable.

3. The combination of a boiler, a feed water pipe, a feed water valve having a part subjected to opposed'fiuid pressures for moving the valve to control the ow of feed water to said boiler, means for establishing the pressure of the outlet side of the valve on one side of said part, means for establishing a fluid pressure of the inlet side of said valve on the other side of said part and for varying the same in response to changes in boiler'ccnditions, and means for maintaining a predetermined fixed' flow resistance between said valve and said boiler.

4. The combination of a boiler, a feed water pipe, a feed water valve having a part subjected to opposed fluid pressures for moving the same to control the flow of feed water to said boiler, means for establishing thevoutlet pressure of said valve against one side of said part, a conduit for conducting pressure fluid to the other side of said part from the inletside of said valve,'a conduit for conducting lpressure fluid to the last named side of said part from the outletside of said valve, means responsive to changes in boiler conditions for controlling the flow through both the last named conduits and means for establishing a .fixed total flow resistance between the outlet side of said valve and said boiler.

5. In combination with a boiler and a feed water pipe therefor, a feed Water regulating valve in said pipe having a part subjected to opposed fluid pressures for moving the same, means for establishing the pressure at the outlet side of said valve on one side of said part, excess pressure means associated with said valve tending to move the same toward closed position, and means controlled by changes in boiler conditions for establishing on the other side of said part a variable fluid pressure derived from said pipe on the inlet side of said valve.

6. In combination with a boiler and a feed Water pipe associated therewith', a valve in said pipe having a part subjected to opposed fluid pressures for moving the same to control the flow of feed water to said boiler, means for establishing the outlet pressure of said valve on one side of said part, excess pressure means associated with said valve tending to move the same to closed position, a conduit for conducting fluid to the other side of said part from the inlet side 'of said valve, a conduit for conducting fluid to the last named side of said part from the boiler side of said valve, and means responsive to changes in boiler conditions for controlling the movement of fluid through said conduits.

7. In combination with av boiler and a feed water pipe therefor, a feed water valve in said pipe having a part subjected to opposed fluid pressures for moving the valve, means for establishing the outlet pressure of said valve against one side of said part to urge said valve toward open position, a conduit for conducting fluid from the inlet side of said valve to the other side of said part, and means responsive to boiler conditions for controlling the movement of fluid through said conduit.

8. In combination with a boiler and a feed water pipe therefor, a valve in said pipe having a part subjected to opposed fluid pressures to move said valve, means for establishing the outlet pressure of said valve on one side of said part, and means for establishing a fluid pressure on the other side of said part and means for varying the same in response to changes in boiler conditions, said last named means being constructed in such a manner that the variable fluid pressure established thereby is no higher throughout its range than the outlet pressure of said valve.

9. In combination with a boiler and a feed water pipe therefor, a valve in said pipe having a part subjected to opposed fluid pressures for moving the valve, a flow resistance between said valve and said boiler, means for establishing the outlet pressure of said valve on one side of said part, a conduit for conducting actuating fluid to the other side 0f said part from a point on the boilei side of said flow resistance, a conduit open to atmosphere and communicating with said last named side of said part, and means for control- Apipe having a part ling the movement of iluidthrough both said conduits.

v10. In combination with a boiler and a feed water pipe therefor, avalve in said pipe having a part subjected to opposed fluid pressures for moving the valve and controlling the flow of feed waterto said boiler, means for establishing the outlet pressure of said valve on one side of said part, a conduit for conductingl actuating fluid to the other side of said partfrom said pipe, a conduit'for conducting fluid from said last named side of said part to atmosphere, and means responsive to changes in boiler conditions for controlling the movement of fluid through said con.- duits.

1l. Inv combination with a boiler and a fee water pipe therefor, a feed water valve in said pipe having a part subjected to opposed fluid pressures for moving the valve to control the ilow of feed water to the boiler, a flow resistance between said valve and said boiler, means for establishing the outlet pressure of said valve against one side of said part to urge the valve toward closed position, excess pressure means tending to move the valve toward open position, and means for establishing a' fluid pressure on the other side of said part and for varying such pressure in response to changes in boiler conditions. i

12. In combination with a boiler and a feed water pipe associated therewith, a feed water valve in said pipe having a part subjected to opposed fluid pressures for moving the same to control the flow of feed water to said boiler, means for establishing the outlet pressure of said valve on one side of said part, pressure means associated with said valve tending to move the same towardv closed position, a conduit for conducting fluid between the other side of said part from a point on the boiler side of said valve, and means for controlling the movement of fluid through said conduit to vary the opening of said valve.

13. In combination with a boiler and a feed water pipe therefor, a feed water valve in said pipe having a part subjected to opposed fluid pressures for moving the same, a fixed flow resistance between said valve and said boiler, means for establishing the pressure at the outlet side of said valve'on one side of said part, pressure means associated with said valve tending to move the same toward closed position, and means responsive to changes in boiler conditions for establishing a variable uid pressure on the other side of said part.

14. In combination with a boiler and a feed water pipe therefor, a feed water valve in said subjected to opposed fluid pressures for moving the valve, means for establishing the outlet pressure of said valve on one side of said part to urge the valve toward open position, and means for establishing a fluid pres- -sure on Vthe other side of said part and for varying such pressure in response to changes in boiler conditions. l

15. In combination with a boiler and a feed water pipe therefor, a feed water valve in said pipe having a part subjected to opposed fluid pressures for moving the valve, means for establishing the outlet pressure of said valve on one side of said part to urge the valve toward open position, a conduit for conducting actuating fluid to the other side of said part from said feed water pipe, means responsive to changes in boiler conditions for controlling the movement of fluid in flow through said valve other than those demanded by boiler conditions whereby to move the Valve to compensate for such changes and by varying one of said opposing uid pressures in response to changes in boiler conditions to change the valve opening to meet the varying requirements of the boiler.

HENRY J. MASTENBROOK. 

